Method for improving execution precision of short stroke at tail part of reversible roughing mill

Abstract

The invention provides a method for improving the short stroke execution precision of the tail of a reversible roughing mill, and relates to the technical field of industrial automation. According to the method, three thermal detectors are arranged at an inlet of the vertical rolling mill, tail short stroke parameters of all passes of the vertical rolling mill are set L2 when a plate blank is discharged from a furnace, and in odd passes, the tail position is tracked according to the set current pass backward sliding and actual speed of the vertical rolling mill when the first thermal detector is detected to be lost; calculating an actual back slip value of the vertical roll and correcting the tracking length according to the distance between the first two thermal detection and the tracking length during the second thermal detection loss, continuing to track the tail, and continuing to correct the back slip value and the tracking position of the tail during the third thermal detection loss; when the distance between the tail part and the vertical roll mill reaches the short stroke starting distance, adjusting the roll gap of the vertical roll according to a set value; and when it is tracked that the tail leaves the vertical roll, the vertical roll mill keeps the current position until the tail of the steel plate leaves the flat roll mill. According to the method, the real backward slip of the vertical rolling mill is measured through multiple thermal detections, and the tail tracking precision and the width control precision are improved.

Description

Technical Field

[0001] The invention relates to the technical field of industrial automation, and in particular to a method for improving the execution accuracy of a short stroke at the tail of a reversible rough rolling mill. Background Art

[0002] During hot rolling, the rough rolling vertical rollers are used to perform short-stroke control on the head and tail of the billet to prevent large heads and tails from appearing in the intermediate billet after rough rolling. The accuracy of short-stroke execution directly affects the width quality and yield rate of the product. At present, a scanning heat detection is generally set in front of the vertical roller mill. The time when the tail of the billet reaches the heat detection is accurately detected by the loss detection of the scanning heat detection. Then, the tail position is tracked by the secondary set vertical roller backslip and vertical roller speed. When the pass is completed, the spacing between the scanning heat detection and the vertical roller is self-learned and corrected according to the actual situation. The backslip of the vertical roller in this pass is indirectly corrected by correcting the spacing between the scanning heat detection and the vertical roller. This correction method is valid for the current pass of the next steel plate, and is invalid for the short-stroke execution of the tail of the current steel plate.

[0003] If the real backslip of the steel plate currently being rolled can be measured, using the real backslip to track the tail of the steel plate will improve the execution accuracy of the short stroke of the tail. Summary of the invention

[0004] In order to solve the above-mentioned technical problems existing in the prior art, an embodiment of the present invention provides a method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill.

[0005] The technical solution is as follows:

[0006] A method for improving the execution accuracy of a short stroke at the tail of a reversible roughing mill, the method comprising:

[0007] S1. Three hot metal detectors are installed at the entrance of the vertical rolling mill. They are named H1, H2 and H3 in descending order of distance from the vertical rolling mill. The distances between H1, H2 and H3 and the vertical rolling mill are D1, D2 and D3 respectively.

[0008] S2, L2 sets the short stroke parameters of each pass of the vertical roller mill when the slab comes out of the furnace;

[0009] S3, odd pass, when the vertical roll or flat roll mill has a load relay signal and H1 is lost, the vertical roll mill starts to slide back according to the current pass set by L2. seti And the actual speed V of the vertical rolling mill real Tracking tail position L real (L real =∑V real Δtk seti , where Δt is the scanning period, V realis the actual speed of the vertical rolling mill, k seti =The back slip value of the current pass of the vertical roller mill set for L2); when H2 is lost, according to the length L of the tail tracking real and the actual distance between H1 and H2 to calculate the actual back slip k of the vertical rolling mill real1 , and use the true distance between H1 and H2 to correct the length L of the tail tracking real , and then continue to track the tail according to the vertical roller mill speed and the calculated actual backslip value; when H3 is lost, further correct the backslip value and tail tracking position;

[0010] S4, when the distance between the tail and the vertical roller mill reaches the length at the beginning of the short stroke, the vertical roller side pressure mechanism starts to act and adjusts the vertical roller gap according to the short stroke parameters set by L2;

[0011] S5. When tracking finds that the tail leaves the vertical roller, the vertical roller mill continues to maintain the current position until the tail of the steel plate leaves the flat roller mill.

[0012] In step S1, the distance between H1 and the vertical roller mill is less than the length of the shortest slab in the normal incoming slabs, the distance between H3 and the vertical roller mill is greater than the starting length of the short stroke of the tail of the vertical roller in the first pass, and H2 is located between H1 and H3, and the distance from H1 is 1 / 3 (D1-D3).

[0013] In step S2, the short stroke parameters of each pass of the vertical rolling mill include: short stroke length L i Length L i The deviation of the roll gap of each position of the vertical roll relative to the body and the back slip value k of the vertical roll mill seti , where i is an odd number, 1≤i≤last pass.

[0014] In step S3, according to the length L of the tail tracking real and the actual distance between H1 and H2 to calculate the actual back slip k of the vertical rolling mill real The method is:

[0015] k real1 =k seti -λ[L real / (D1-D2)-1]

[0016] Where λ is the correction coefficient, the value range is 0.6~0.8, and -0.15≤λ[L real / (D1-D2)-1]≤0.15, and 0.7≤k real1 ≤0.9; k seti is the first pass backslip value of the vertical rolling mill;

[0017] k real1It is the backward slip value after the first correction for odd track times.

[0018] The length L of the tail tracking is corrected by using the real distance between H1 and H2 real Specifically, at the moment when H2 is lost, the distance between H1 and H2 is taken as the tail tracking length.

[0019] When H3 is lost in step S3, the method for further correcting the backslip value and the tail tracking position is as follows:

[0020] k real2 =k real1 -λ[L real / (D1-D3)-1]

[0021] Where λ is the correction coefficient, the value range is 0.6~0.8, and -0.15≤λ[L real / (D1-D3)-1]≤0.15, and 0.7≤k real2 ≤0.9;

[0022] k real2 It is the second corrected backslip value for odd track times.

[0023] The tail tracking position correction is specifically as follows: at the moment when H3 is lost, the distance between H1 and H3 is taken as the tail tracking length.

[0024] In step S4, when the distance between the tail and the vertical rolling mill reaches the length at the beginning of the short stroke, it means D1-L real ≤L i , where L i The short stroke starting length (from the tail end) of the current pass of the vertical rolling mill is set for L2.

[0025] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0026] In the above scheme, L2 is used to set the short stroke length of the rough rolling tail and the deviation of the roll gap of each position within the length relative to the main body. Three heat detectors (i.e., hot metal detectors) are set in front of the rough rolling vertical mill. L1 calculates the backslip of the vertical mill according to the actual distance between the three heat detectors, the heat detection failure state, the load relay signal of the vertical roll and the flat roll, and the actual speed of the vertical roll. The tail position of the steel plate is accurately tracked according to the backslip, and the actual roll gap of the vertical roll is controlled according to the tail position to meet the requirements of L2. Based on the backslip set at the second level, this method uses multiple heat detectors to correct and calculate the real backslip of the slab, which can improve the tail tracking accuracy of the steel plate currently being rolled, thereby improving the width control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a flow chart of a method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0030] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0031] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0032] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0033] The embodiment of the present invention provides a method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill. Figure 1 The method flow chart of improving the execution accuracy of the short stroke at the tail of the reversible roughing mill is shown, and the method may include the following steps:

[0034] S1. Three hot metal detectors are installed at the entrance of the vertical rolling mill. They are named H1, H2 and H3 in descending order of distance from the vertical rolling mill. The distances between H1, H2 and H3 and the vertical rolling mill are D1, D2 and D3 respectively.

[0035] S2, L2 sets the short stroke parameters of each pass of the vertical roller mill when the slab comes out of the furnace;

[0036] S3, odd pass, when the vertical roll or flat roll mill has a load relay signal and H1 is lost, the vertical roll mill starts to slide back according to the current pass set by L2. seti And the actual speed of the vertical roller mill tracks the tail position; when H2 is lost, according to the tail tracking length L realand the actual distance between H1 and H2 to calculate the actual back slip k of the vertical rolling mill real1 , and use the true distance between H1 and H2 to correct the length L of the tail tracking real , and then continue to track the tail according to the vertical roller mill speed and the calculated actual backslip value; when H3 is lost, further correct the backslip value and tail tracking position;

[0037] S4, when the distance between the tail and the vertical roller mill reaches the distance at which the short stroke starts, the vertical roller side pressure mechanism starts to act and adjusts the vertical roller gap according to the short stroke parameters set by L2;

[0038] S5. When tracking finds that the tail leaves the vertical roller, the vertical roller mill continues to maintain the current position until the tail of the steel plate leaves the flat roller mill.

[0039] In the specific application process, it is assumed that the distance D1 of H1, H2 and H3 from the vertical roller mill is 6m, D2 is 4m, and D3 is 2m. The second level setting is 0.75 for the vertical roller backslip of a certain odd pass, 1.8m for the tail short stroke starting position, and λ is 0.7. When H2 is lost, the tail tracking length L real is 2.2m, then k real1 =0.75-0.7x[2.2 / (6-4)-1]=0.75-0.07=0.68, take k real1 =0.7, corrected L real =6m-4m=2m; when H3 is lost, L real =3.95m, k real2 =0.7-0.7x[3.95 / (6-2)-1]=0.70875, take k real2 =0.70875, modified L real =6m-2m=4m; when L real =6-1.8=4.2m, the short stroke starts to execute.

[0040] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill, characterized in that: The method comprises: S1. Three hot metal detectors are installed at the entrance of the vertical rolling mill. They are named H1, H2 and H3 in descending order of distance from the vertical rolling mill. The distances between H1, H2 and H3 and the vertical rolling mill are D1, D2 and D3 respectively. S2, L2 sets the short stroke parameters of each pass of the vertical roller mill when the slab comes out of the furnace; S3, odd pass, when the vertical roll or flat roll mill has a load relay signal and H1 is lost, the vertical roll mill starts to slide back according to the current pass set by L2. seti And the actual speed V of the vertical rolling mill real Tracking tail position L real ; When H2 is lost, according to the length L of the tail tracking real and the actual distance between H1 and H2 to calculate the actual back slip k of the vertical rolling mill real1 , and use the true distance between H1 and H2 to correct the length L of the tail tracking real , and then continue to track the tail according to the vertical roller mill speed and the calculated actual backslip value; when H3 is lost, further correct the backslip value and tail tracking position; S4, when the distance between the tail and the vertical roller mill reaches the length of the tail short stroke, the vertical roller side pressure mechanism starts to act and adjusts the vertical roller gap according to the short stroke parameter set by L2; S5. When tracking finds that the tail leaves the vertical roller, the vertical roller mill continues to maintain the current position until the tail of the steel plate leaves the flat roller mill.

2. The method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill according to claim 1, characterized in that: In step S1, the distance between H1 and the vertical roller mill is less than the length of the shortest slab in the normal incoming slabs, the distance between H3 and the vertical roller mill is greater than the starting length of the short stroke of the tail of the vertical roller in the first pass, and H2 is located between H1 and H3, and the distance from H1 is 1 / 3 (D1-D3).

3. The method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill according to claim 1, characterized in that: In step S2, the short stroke parameters of each pass of the vertical rolling mill include: the short stroke starting length L i Length L i The deviation of the roll gap of each position of the vertical roll relative to the body and the back slip value k of the vertical roll mill seti , where i is an odd number, 1≤i≤last pass.

4. The method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill according to claim 1, characterized in that: The tail position L in step S3 real The calculation formula is as follows: L real =∑V real Δtk seti , where Δt is the scanning period, V real is the actual speed of the vertical rolling mill, k seti The back slip value of the current pass of the vertical roll mill set for L2.

5. The method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill according to claim 1, characterized in that: In step S3, according to the length L of the tail tracking real and the actual distance between H1 and H2 to calculate the actual back slip k of the vertical rolling mill real1 The method is: k real1 =k seti -λ[L real / (D1-D2)-1] Where λ is the correction coefficient, the value range is 0.6~0.8, and -0.15≤λ[L real / (D1-D2)-1]≤0.15, and 0.7≤k real1 ≤0.9; k seti is the current pass back slip value of the set vertical roller mill; k real1 It is the backward slip value after the first correction for odd track times.

6. The method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill according to claim 1, characterized in that: The length L of the tail tracking is corrected by using the real distance between H1 and H2 real Specifically, at the moment when H2 is lost, the distance between H1 and H2 is taken as the tail tracking length.

7. The method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill according to claim 1, characterized in that: When H3 is lost in step S3, the method for further correcting the backslip value and the tail tracking position is as follows: k real2 =k real1 -λ[L real / (D1−D3)−1] Where λ is the correction coefficient, the value range is 0.6~0.8, and -0.15≤λ[L real / (D1-D3)-1]≤0.15, and 0.7≤k real2 ≤0.9; k real2 It is the second corrected backslip value for odd track times; The tail tracking position correction is specifically as follows: at the moment when H3 is lost, the distance between H1 and H3 is taken as the tail tracking length.

8. The method for improving the execution accuracy of the short stroke at the tail of a reversible roughing mill according to claim 1, characterized in that: In step S4, when the distance between the tail and the vertical rolling mill reaches the length at the beginning of the short stroke, it means D1-L real ≤L i , where L i The starting length of the tail short stroke of the current pass of the vertical roller mill is set to L2.

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